73978016121 has 45 divisors (see below), whose sum is σ = 113087556021. Its totient is φ = 48194274888.

The previous prime is 73978016107. The next prime is 73978016131. The reversal of 73978016121 is 12161087937.

The square root of 73978016121 is 271989.

It is a perfect power (a square), and thus also a powerful number.

73978016121 is a `hidden beast` number, since 7 + 397 + 80 + 161 + 21 = 666.

It is not a de Polignac number, because 73978016121 - 2¹⁵ = 73977983353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (73978016131) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 115051026 + ... + 115051668.

Almost surely, 2^73978016121 is an apocalyptic number.

73978016121 is the 271989-th square number.

73978016121 is the 135995-th centered octagonal number.

It is an amenable number.

73978016121 is a deficient number, since it is larger than the sum of its proper divisors (39109539900).

73978016121 is an frugal number, since it uses more digits than its factorization.

73978016121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392 (or 693 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The spelling of 73978016121 in words is "seventy-three billion, nine hundred seventy-eight million, sixteen thousand, one hundred twenty-one".